vestibule

n. A small bodily cavity at the entrance to a larger cavity, such as the vestibule of the inner ear, which is the fluid-filled chamber between the three canals of the inner ear and the cochlea and contains the utricle and saccule; or the vaginal vestibule, which is the opening between the labia minora at the entrance to the vagina and into which the urethra and greater vestibular glands open.